The first patient on our operating schedule is a 65-year old male admitted for planned right hemicolectomy due to diverticulitis. The operation will be performed under general anaesthesia. This procedure is indicated for neuromuscular monitoring (see help). You are a young anaesthetist with access to monitoring device used for measuring of depth of neuromuscular blockade - relaxometer with accelerometric evaluation of muscle response (TOF-Watch® SX), which you will be using for the first time in your career. Where would you place the electrodes of this device?
Age = 65 yrs; Weight = 213 lb; Height = 5ft 12in (Lean Boby Mass = 154 lb)
healthy, with no acute illness and no history of chronic illnesses, smoker (20 cigarettes per day for 20 years) , ECG and CXR of heart and lungs without pathology
ASA II, Mallampati 1, no obvious risk of difficult airway management
Indications for monitoring of NMT
The most up to date recommendation is to monitor the depth of relaxation every time while using non-depolarising muscle relaxant.
Earlier recommendations for monitoring of neuromuscular transmission used to be:
Accessibility to monitoring apparatus in your hospital
Abnormal pharmacokinetics of neuromuscular blockers: kidney/liver dysfunction, severe systemic disease, age (very young or elderly patients)
Abnormal pharmacodynamics of neuromuscular blockers: Neuromuscular diseases, myasthenia gravis, congenital myasthenic syndrome
If we want to avoid pharmacological reversal due to some pathological condition: Ischaemic heart disease, Bronchial Asthma
If we are in need of immediate post-operative restoration of muscular strenghth: obesity, severe pulmonary illness
Procedures lasting more than 90 minutes
Application of NM-blockers via infusion
Usage of long-lasting neuromuscular blockers
ASA - stands for American Society of Anaesthesiologists, classification used for evaluating the general physical status of the patient.
